Sound reproducing device for playing a record disc having a plurality of recorded grooves

ABSTRACT

A sound reproducing device is disclosed in which an index tracking portion formed on a record disc consists of a notch on the continuous flange of rotational periphery of a record disc unit. A center pin of the device is normally urged outside of a casing by a spring which also urges an index setting arm with a push button type index setting rotary knob supported on the tip end of said center pin. An index setting portion consists of a plurality of openings formed in the casing and arranged along the rotational plane of said record disc unit. The index setting arm has a resilient engaging hook on its lower tip end, the engaging hook directed toward the rotational cetner of the record disc unit. The engaging hook engages with the flange of the record disc unit where a specific index setting portion is selected by rotation of the push button type index setting knob. Pushing the index setting knob down makes the engaging hook pass through an index setting openings. The center pin keeps a speaker unit out of engagement with a pickup such that the pickup returns to the starting point of sound reproduction. The engaging hook returns through the index tracking portion when the index tracking portion comes on the engaging hook by rotational movement of the record disc unit, causing the center pin to retract so as to impart stylus pressure to the stylus by returning the speaker unit by a stylus pressure spring.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 327,762, filed Mar. 23, 1989, now issued as U.S. Pat. No.4,876,678.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a sound reproducing device for playing arecord disc having a plurality of recorded grooves. More particularly,the present invention relates to such a sound reproducing devicecomprising an index tracking portion which is a notch formed by cuttingaway a part of a flange continuously formed around the periphery of arotary record disc unit, and a center pin rotatably supporting therecord disc unit which center pin carries a push button type rotary knobthereon exposed outside a casing in such a manner that the center pin isnormally urged together with the push button type rotary knob, towardthe outside of the casing by a spring biasing an indexing arm.

2. Description of the Prior Art

A simplified sound reproducing device, capable of selectivelyreproducing a specific recorded item on a record disc having a pluralityof recorded grooves each carrying respective recorded items, has beendeveloped and becomes well known, e.g., such as described in JapanesePatent Examined Publication No. Sho 51(1976)-19763, corresponding toU.S. Pat. No. 3,712,629 and to British Patent Specification No.1,336,749.

This prior art simplified sound reproducing device functions in such amanner that:

if an operator depresses a selection pole for indexing a specific itemon a record disc, it acts to push an inclined face of a stylus forcereleasing wheel to move a stylus force releasing pole to make the stylusforce releasing wheel rotate, and then a stylus force releasing polecarried by the stylus force releasing arm travels together with thestylus force releasing wheel and raises a speaker unit, allowing apickup to return to the starting point of sound reproduction of aspecific record disc unit.

At the same time, the selection pole locks a stopper pin disposed in therecord disc unit and tentatively stops the rotation of the record discunit, thereby locating the specific recorded groove at a position wherethe pickup, which has already returned to the aforesaid starting pointof reproduction, can engage the recorded groove, while by the operator'sreleasing of the depression of the selection pole, the stylus forcereleasing pole will retract together with the stylus force releasingwheel and release the supply of current to the speaker unit, therebyimporting a stylus force to the pickup.

Accordingly, in this prior art device, a stylus force can be undesirablyimparted to the pickup halfway through its returning travel to thestarting point of sound reproduction, and thereby the desired recordgroove cannot be selected, unless the operator keeps his depression ofthe selection pole until its stopper pin engages the specific selectionpole which has been depressed. The period of time required for effectingengagement between the stopper pin and the selection pole variesdepending upon the relative position between the stopper pin and theselection ple, and therefore, the operator himself cannot forecast thenecessary period of time. Consequently, the sound reproducing devicementioned above has drawbacks with respect to its lack of bothreliability in selection and fast operability.

A device disclosed in Japanese Laid-Open (unexamined) Patent PublicationNo. Sho 60(1985)-50701, corresponding to U.S. Pat. No. 4,482,990, hasbeen provided, with the intention of obviating the aforesaid drawbacks.However, this device was found to be disadvantageous in simplifying thedevice, because of the fact that the stylus force releasing means andthe indexing means were complicated.

Another sound reproducing device having improved steadiness of selectionand rapidity of operation has been disclosed by Japanese Laid-Open(unexamined) Patent Publication No. Sho 60(1985)-76001, corresponding toU.S. Pat. No. 4,541,085, with an intention to obviate the aforesaiddrawbacks.

However, this device was also found to be disadvantageous insimplifying, because the stylus force releasing means and the indexingmeans were also complicated.

Moreover, a simplified sound reproducing device capable of selectivelyplaying a record disc having a plurality of recorded grooves and furtherprovided with a rotary dial for selecting the item to be reproduced bydirecting it to the item to be selected has already been developed andhas been disclosed by Japanese Laid-Open (unexamined) Patent PublicationNo. Sho 58(1983)-17501, corresponding to U.S. Pat. No. 4,433,404 and toBritish Patent No. 2,103,006-B.

However, this device has also proved to be unsatisfactory, particularlyas a toy for training infants, that is, even if the user turns therotary dial to the indexing mark or symbol to be played, the rotary dialwill start rotation following the rotation of the record disc unit,thereby the indicated item which has just been selected for playingwould be unplayed.

In addition, a further device having a center pin for rotatablyreceiving a record disc unit in which the center pin may be depressedfor the purpose of releasing the stylus force has also been proposed andpublicly known in Japanese Laid-Open (unexamined) Patent Publication No.Sho 57(1982)-152568, corresponding to U.S. Pat. No. 4,404,668.

However, this device has also drawbacks that it uses a plurality ofselecting poles and many parts and thereby becomes very complicated inconstruction.

PROBLEMS IN THE PRIOR ART

Such sound reproducing devices as disclosed by the aforesaid JapaneseLaid-Open (unexamined) Patent Publication Nos. Sho 60(1985)-50701, 76001and Sho 58(1983)-17501, respectively, have drawbacks in common,complicated construction and being disadvantageous for simplifying thiskind of device.

Particularly, the device disclosed by the Japanese Laid-Open(unexamined) Patent Publication No. Sho 57(1982) -17501 has a defectalready referred to that the item that has just been selected andreproduced would become impossible to identify, which is not suitablefor the purpose of training and has been an urgent problem to be solved.

The present invention aims to solve the above-mentioned problems of theprior art. Accordingly an object of the present invention is to providea sound reproducing device which can securely select a desired recordedgroove.

Another object of the present invention is to provide a soundreproducing device capable of performing rapid operation. A furtherobject of the present invention is to provide a sound reproducing deviceof simplified construction. A still further object of the presentinvention is to provide a sound reproducing device suitable for trainingpurposes in which a sound reproduction indexing symbol, once selected,could remain indicated after the selected item has been finished untilthe time when the next indexing is done for the purpose of selectinganother item.

SUMMARY OF THE INVENTION

The present invention provides an improved and simplified soundreproducing device for playing a record disc having a plurality ofrecorded grooves thereon.

A sound reproducing device according to the present invention comprises:

(a) a casing;

(b) a record disc unit disposed in the casing and having a plurality ofrecorded grooves which define a recorded face thereof, the record discunit having a circular periphery with an index tracking portion formedthereon, the casing having a plurality of index setting openings formedtherein along the periphery of the record disc, the number of indexsetting openings corresponding to the number of recorded grooves;

(c) a center pin disposed in the casing, the disc unit being rotatablysupported on the center pin;

(d) a speaker unit comprising a speaker cone and a sound transmittingmember attached thereto;

(e) means for mounting the speaker unit to the casing, the mountingmeans allowing for swingable movement of the speaker unit toward or awayfrom the recorded face of the record disc unit;

(f) a stylus force spring disposed in the casing for urging said soundtransmitting member toward the recorded face of said record disc unit;

(g) a pickup interposed said sound transmitting member and said recorddisc unit;

(h) means for urging the pickup radially outwardly with respect to therecorded face;

(i) means for rotating the disc unit;

(j) a rotatable index setting knob disposed at an end of the center pin;

(k) an index setting arm supported by said index setting knob, the indexsetting arm having an engaging hook thereon for insertion into the indexsetting openings; and

(l) a fixed indexing ring disposed outside the casing and bearingindicia thereon for showing items recorded in the grooves of said recorddisc unit.

The center pin mentioned above is coupled to the index setting arm andthese two members can be advanced or retracted together, and whenadvanced the speaker unit can be moved away from the record disc unitagainst the stylus force.

In the simplified sound reproducing device of this invention, the itemsof sound reproduction shown on the indexing ring correspond to the indexsetting portions or recesses, while the index tracking portion is formedas a notch by cutting away a part of the upper flange formedcontinuously along the outer periphery of the record disc unit.

The center pin engages the push button type index setting knob which isdisposed partly outside the casing. The index setting knob and the indexsetting arm can be moved integrally with the center pin only in an axialdirection of the center pin and are normally urged outward by the springwhich urges the index setting arm to retract. The index settings areformed as a plurality of apertures distributed in the casing along thesurface of the rotary record disc unit.

The index setting arm can be located above any one of the index settingopenings or can be recessed by turning the push button type indexsetting knob, which is integral with the indexing arm, in the rotationaland axial direction, so that the index setting arm can be advancedtogether with the center pin when the push button type index settingknob is depressed against the force of spring. In addition the indexsetting arm has at its forward tip end an engaging hook which canelastically deform and pass over the outer edge portion of the upperflange of the record disc unit and then can slidably catch the flangewhen it resiliently returns to its original shape. In addition, theindex setting arm can be returned to the original position by virtue ofthe resilient force given by the spring when the index tracking notcharrives at the portion just above the engaging hook effected by therelatively sliding rotation of the record disc unit, thereby releasingthe center pin from the depressed position, releasing in turn thespeaker unit, and the pickup can be placed under the stylus force.

The simplified sound reproducing device as constructed in aforesaidmanner can function as follows:

At first, the push button type index setting knob is turned so that thearrow head is pointed to the desired item shown in the fixed indexingring. The index setting arm within the casing is rotated and positionedat one of the index setting recesses by this rotation of the knob, theselected recess corresponding to the selected item on the fixed indexingring. Next, the push button type index setting knob is depressed to makethe index setting arm move downwardly together with the center pin,which urges the speaker unit against the resilient force imparted by thestylus force spring.

This downward movement of the center pin releases the stylus forceapplied to the pickup, allowing the pickup to return to the staringpoint of sound reproduction. At this moment, the terminating switchloses the support given by the pickup and begins to supply a power tothe motor, thus resulting in rotation of the record disc unit. When theindex setting arm moves downwardly together with the center pin, theengaging hook disposed at the frontmost end of the arm passes over andslidably catches the peripheral edge of the upper flange of the recorddisc unit and holds both the index setting arm and the center pin in thedepressed state. Under this state, the record disc unit still continuesrotation but no stylus force is applied to the pickup.

In addition, since the index setting recesses or openings aredistributed along the rotating circle of the index setting arm and therecord disc unit is received around the center pin while beingindependent of rotation of the center pin, the index setting arm and theengaging hook can maintain the set position.

When the index tracking portion formed as a notch on the periphery ofthe record disc arrives, by the rotation of the record disc unit, at apoint just above the engaging hook, the index setting arm having theengaging hook thereon is allowed to return by passing through the notchof the index tracking portion to the original position above the recorddisc unit, being urged by the spring. This allows the center pin toreturn to its original position and releases its downward pressure onthe speaker unit, which moves upward placing the pickup under stylusforce. The record groove with which the pickup engages is thus startedon its selected sound reproduction.

The timing necessary for imparting a stylus force to the pickup variesdepending upon which index setting position the engaging hook of theindex setting arm is positioned at, and yet the selected index settingposition has a specific spatial relation with respect to the position ofthe introductory part of each record groove, so it is possible to makethe pickup engage the desired groove relying on the selected item shownon the fixed indexing ring and the rotation of the push button typeindex setting knob.

Since the push button type index setting knob is constructed to bemovable free from the rotation of the record disc unit, it does notrotate with the record disc unit, therefore, a selected position of thefixed indexing ring does not vary even when the sound reproduction ofthe selected item has been finished.

It has been rendered possible, according to the present invention, toprovide a sound reproducing device by which not only any desired recorddisc can be surely selected but also satisfying fast selection andsimplified construction objectives.

Furthermore, it is possible with the present invention for the recordeditem which has been selected and reproduced to be indicated even afterit has been finished, unlike the prior art devices, and the device ofthe present invention is therefore particularly suitable as a toy fortraining purposes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a preferred embodiment of thepresent invention,

FIG. 2 is a sectional side view taken along line 2--2 of FIG. 1,

FIG. 3 is a top plan view with the chassis and housing having been takenaway,

FIG. 4 is a partial view seen along line 4--4 of FIG. 2, and

FIG. 5 is a partial perspective view showing a record disc unit, a pushbutton type rotary knob and an indexing arm.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, an outside appearance of a sound reproducing deviceaccording to the present invention is shown, in which a casing 1includes a chassis 1a, an operating box 1c integrally stacked above thechassis 1a and a housing 1b placed stacked beneath the chassis 1a.

The casing 1, as shown in FIG. 2, has formed in the housing 1b a speakerbox 31 having a plurality of slits 30 for emitting reproduced soundsoutside. A partition plate 1d extends within the chassis 1a and an upperdeck 1e also extends above the partition plate 1d within the chassis 1a.

As can be seen from FIGS. 1 and 2, the operating box 1c as shown, has asurface which contains an annular fixed indexing ring 53. The surface ofthe ring 53 has a plurality of recorded items which are indicated bysymbols such as the pictures and accompanying letters shown in FIG. 1.Disposed within the inner central part of the indexing ring 53, is apush button type rotary index setting knob 51, the top face of which hasan arrow mark 54 thereon. The index setting knob 51, as clearly shown inFIG. 2 is rotatable with respect to the interior members of the casing1, is axially movably assembled to the casing 1, and carries a radiallyprojecting index setting arm 20 attached thereto as an integrally formedpiece. This index setting arm 20 is bent at an intermediate portionthereof downwardly along a line parallel to the axis of the rotary indexsetting knob 51, and the lower tip end of the index setting arm 20 bearsan integrally formed and radially inwardly bent tongue-like elasticengaging hook 24.

A mechanism disposed below the partition plate 1d of the chassis 1a canbe observed in FIG. 3, that is, a tone arm 29 having a pickup 13 at itsforward end and which is pivotally mounted at its rear end to a pivotpin 56. Mounted at the right side of the partition plate 1d in FIGS. 2-3is a motor 3, the output shaft S of which is directed toward the upperdeck 1e, as can be seen from FIG. 2. Moreover, mounted on the partitionplate 1d is a Y-shaped sound transmitting member 8 which together with aspeaker cone 7, makes up a speaker unit 9.

The sound transmitting member 8 is swingably supported at both tip ends62, 64 of its bifurcated arm 66 so as to be swingably movable toward oraway from the reverse face of the partition plate 1d. The remainingportion of the sound transmitting member 8 extends so that it contactsthe pickup 13. The speaker unit 9 as shown by FIG. 2, is normally urgedupwardly by a stylus force spring 10 located at the central part of thespeaker box 31, so as to urge the pickup 13 upwardly as seen in FIG. 2.

In FIGS. 2 and 3, a reproduction terminating switch 15 is positioned inthe electrical circuit to the motor 3 in such a manner that it isactivated by the pickup 13; opens the circuit; and, cuts off current tothe motor when the pickup 13 comes to the position where it finishes thesound reproduction.

The reproduction terminating switch 15 is positioned near thereproduction terminating point 14 adjacent to the center of the recordedface of the record disc unit 5.

An opening 28 is formed in the partition plate 1d for the pickup, bymeans of which the pickup 13 is allowed to pass through the partitionplate 1d to contact the record disc 5.

As shown in FIG. 2, a battery Ba energizes the motor 3.

As shown in FIGS. 2 through 5, a record disc unit 5 carries eightspiralled recorded grooves 2.

FIG. 4 shows only the introductory part of each of these record grooves,the number of which corresponds to the number of indexed items shown onthe indicator dial 53.

The pickup 13 is normally urged by a return spring 11 radially outwardlywith respect to the disc 5 toward the starting point of soundreproduction 12 and to a direction laterally away from the recorded faceof the record disc 5.

The return spring 11 is wound around a pin 56 at the rear end of thetone arm 29, the pin 56 disposed as a swing axis of the tone arm 29.

As particularly seen in FIG. 2, the center pin 50 is received and guidedby the partition plate 1d and the upper deck 1e so as to be axiallyreciprocally movable both in advancing and retractive movement thereof.Around the center pin 50, the record disc unit 5 is rotatably supportedin a manner allowing free rotation and advancing and retracting movementof the center pin 50 but is restrained from its axial movement by beingclamped between the partition plate 1d and the upper deck 1e. Eightrecorded spiral grooves are formed on the record disc unit 5 which isformed with flanges F at the periphery of both the axially upper andlower faces thereof. An annular groove 58 defined between these twoflanges is used as a pulley groove, accommodating a drive belt 34. Apart of the upper flange F is cut away axially and radially at itsradially outer end to form an indexing tracking portion 19 as seen inFIGS. 2, 4, and 5.

A boss 35 is provided having a through hole formed therein at the centerof the record disc unit 5, through which the center pin 50 is passed.The boss 35 extends both above the upper face and below the reverse faceof the record disc 5, and functions as a thrust shaft located betweenthe upper deck 1e and the partition plate 1d for limiting the axialmovement of the record disc unit 5.

The above-mentioned push button type rotary index setting knob 51 isfixedly attached on the top end of the center pin 50 and is urgedaxially toward the outside of the casing 1 together with the center pin50 by a coil spring 27 supported on the upper deck 1e, and the indexsetting arm 30 with the engaging hook 24 formed at the lower tip endthereof together are also normally urged upwardly by the spring 27 sincethey are attached to the knob 51. The knob 51 has an integral flange 60extending radially outwardly as seen in FIG. 2 which retains the lowerportion of the knob 51 inside the casing 1.

The lower tip end of the center pin 50 extends to a position above thesound transmitting member 8 of the speaker unit 9 and is able to pushdown the sound transmitting member 8 when the center pin 50 is moveddownwardly.

In a state where the housing 1b, record disc unit 5, chassis 1a and theoperating box 1c are assembled together, the pickup 13 moves upwardly bypassing through the opening 28 toward the recorded face of the recorddisc unit 5 so as to be engageable with the record groove 2. At thismoment, the biasing force of the stylus spring 10 is imparted throughthe sound transmitting member 8 to the pickup 13 as a stylus force, andthe pickup 13 is positioned between the sound transmitting member 8 andthe record disc unit 5 and is able to travel along the record groove 2between the starting point 12 and the end point 14 of sound reproductionof the record disc unit 5.

The engaging hook 24 of the index setting arm 20 is normally situatedabove the upper flange F of the record disc unit 5 when the push buttontype rotary index setting knob 51 is not depressed and the index settingarm 20 is not yet lowered as shown by the solid line in FIG. 2. When thepush button type rotary knob 51 is depressed and the index setting arm20 is lowered as shown by the phantom line in FIG. 2, the engaging hook24 moves below the upper flange F. In particular, the engaging hook 24is arranged so that it may elastically deform by contact with the outerperiphery of the upper flange F during its downward stroke from itsupper position to the lower position and then the hook 24 slidablyengages the lowerside of the upper flange F when it arrives at theportion therebelow, as illustrated in phantom in FIG. 2.

Since the engaging hook 24 is made to have a smaller width than that ofthe notch of the index tracking portion 19, it may pass through thenotch axially downwardly when it comes just above the notch of the indextracking portion 19.

A resilient belt 34 is extended around and between the groove 58 of thepulley of the record disc unit 5 and around the output shaft S of themotor 3.

As particularly shown in FIG. 4, a plurality of index setting openings17 are formed in the upper deck 1e of the casing 1 along the circularperiphery of the record disc unit 5.

These index setting openings 17 are eight in number in the embodimentshown, corresponding in number to the recorded grooves 2 formed on therecord disc unit 5.

The distribution of these index setting openings 17 follows the specificpositional relationship with respect to the position of the pickup 13which has already returned to the starting point of sound reproduction12.

Also, the position of an index setting opening 17 corresponds, withrespect to each circular angle, to each of the recorded items shown inthe fixed indexing ring 53 fixed to the casing 1.

The sound reproducing device of the present invention operates in themanner mentioned below.

The pickup 13 when it has just finished reproduction of a specificrecord groove 2 stays at the reproduction end point 14, opens theterminating switch 15, and the current to the motor 3 is cut off.

Then, a user turns the push button type rotary index setting knob 51with its arrow mark 54 to be directed to the item to be reproduced, forexample, mark A as shown in FIG. 1, and then the engaging hook 24 formedat the tip end of the index setting arm 20 is positioned, as shown inFIGS. 2 and 4, above the index setting opening 17 indicated by the arrowmark 54 of the push button type rotary knob 51.

Subsequent depression of the push button type rotary index setting knob51 against the resilient force of the spring 27 results in lowering ofthe rotary index setting knob 51 to the interior of the casing 2 withaccompanying downward advancing of the center pin 50 together with theengaging hook 24 of the index setting arm 20. The engaging hook 24 goesdown through the selected index setting opening 17. Due to the downwardadvancing of the center pin 50, the lowermost end of the center pin 50pushes down the speaker unit 5 against the stylus force spring 10, andby virtue of this motion the stylus force imparted to the pickup 13 isreleased so that the pickup 13 can be urged by the return spring 11 tothe starting point of sound reproduction 12. Upon moving of the pickup13 away from the end point of reproduction 14, the terminating switch 15closes since it has lost its support to keep it open, and then currentis supplied to the motor 3 to rotate it, thereby beginning rotation ofthe record disc unit 5.

Descending movement of the engaging hook 24 effected by the user'sdepression on the push button type rotary index setting knob 51 movesthe engaging hook 24 through the index setting opening or recess 17formed in the upper deck 1e down to a position where it can contact theperipheral edge of the upper flange F of the record disc unit 5.

Further downward movement of the engaging hook 24 gives rise to itselastic deformation due to the fact that it is forcibly pushed againstthe face of the upper flange F and it passes over the edge of the flangeand finally reaches the portion below the upper flange F as shown inphantom in FIG. 2.

If the user stops depression and takes his hand away from the pushbutton type rotary knob 51, the engaging hook 24 is allowed to return bythe resilient force of the spring 27 and slidably catches the flange Ffrom its downside. Due to this movement, the index setting arm 20, pushbutton type rotary index setting knob 51 and the center pin 50 are heldtogether at the position to which they have advanced downwardly, andthus the position to which the speaker unit has been lowered, namely,where the stylus force applied on the pickup is released, can bemaintained.

As explained heretofore, when the terminating switch 15 is closed,current is supplied to the motor 3, and the record disc unit 5 will turnin the direction shown by the arrow line shown in FIG. 4. However, sincethe record disc unit 5 and the center pin 50 are constructed to berotated freely of each other, the position of the engaging hook 24 willnever be varied. As a consequence, if the index tracking notch 19 turnsslidable with respect to the engaging hook and arrives at the positionwhere the engaging hook 24 is located, the engaging hook 24 will returnupwardly to the position above the upper flange F by passing through theindex tracking notch 19.

By this movement, the center pin 50 retracts upwardly urged by thespring 27 and releases its pressure on the speaker unit 9, and owing tothe direction of rotation of the record disc 5a, the pickup 13 willengage the introductory portion of the specific record groove 2a asshown in FIG. 4.

By this engagement, the desired recorded item can be reproduced.

When the sound reproduction has been finished upon arrival of the pickup13 at the end point 14 of sound reproduction, the pickup 13 contacts theterminating switch 15 again and opens the circuit.

Since the record disc unit 5 is rotatably supported independently of thecenter pin 50, the push button type rotary index setting knob 51 doesnot rotate with the record disc unit 5. Consequently, the push buttontype rotary index setting knob 51 still indicates the indexed item evenwhen the reproduction of the specific item has been finished. Thisfeature is very helpful in using the device of the present invention asan educational toy.

As explained heretofore, once the desired item has been selected byturning the push button type rotary index setting knob 51, the engaginghook will catch the flange F of the record disc unit 5 and it is able tohold the state where the stylus force has been released and it is alsopossible for it to exactly remain on the indexed item which has justbeen reproduced.

Although the present invention has been described herein with respect tospecific embodiments thereof, it will be understood that the foregoingdescription is intended to be illustrative, and not restrictive. Manymodifications of the present invention will occur to those skilled inthe art. All such modifications which fall within the scope of theappended claims are intended to be within the scope and spirit of thepresent invention.

Having, thus, described the invention, what is claimed is:
 1. Asimplified sound reproducing device comprising:(a) a casing; (b) arecord disc unit disposed in the casing and having a plurality ofrecorded grooves thereon which define a recorded face thereof; (c) acenter pin disposed in the casing, the disc unit being rotatablysupported on the center pin; (d) a pickup for playing a selected grooveon the recorded face; (e) means for rotating the disc unit about thecenter pin. (f) a fixed indexing ring on the outside of the casing, theindexing ring having a plurality of indexing symbols thereon; (g) arotatable index setting knob disposed at an end of the center pin andpartially extending outside of the casing to allow grasping thereof by auser of the device; the index setting knob comprising means forindicating a currently selected indexing symbol on the indexing ring;and (h) means for fixing a given orientation of the indicating means,once selected, during playing of a selected groove and thereafter untilanother indexing symbol is selected; wherein playing of a selectedgroove is effected by rotating the disc unit, with the means forrotating, about the center pin with the pickup engaged in the selectedgroove.
 2. The device of claim 1, wherein the index setting knob isrotatable independently of the record disc unit.
 3. The device of claim1, further comprising a terminating switch proximate the center pin forcontacting by the pickup.
 4. A simplified sound reproducing devicecomprising:(a) a casing; (b) a record disc unit disposed in the casingand having a recorded face thereof and an indexing tracking portionformed on the periphery of said record disc unit; (c) a center pindisposed in the casing, the center pin being received and guided in thecasing so as to be axially and reciprocally movable both in advancingand retracting movement thereof, the disc unit being rotatably supportedon the center pin; (d) a pickup for playing a selected groove on therecord face; (e) a fixed indexing ring on the outside of the casing, theindexing ring having a plurality of indexing symbols thereon; (f) arotatable index setting knob disposed at an end of the center pin andpartially extending outside of the casing, to allow grasping thereof bya user of the device; the index setting knob comprising means forindicating a currently selected indexing symbol on the indexing ring;and (g) means for fixing a given orientation of the indicating means,once selected, during playing of a selected groove and thereafter untilanother indexing symbol is selected; the means for fixing a givenorientation of the indicating means comprising a plurality of indexsetting openings formed in said casing along the periphery of saidrecord disc, the number of which corresponds to the number of recordedgrooves, and an indexing setting arm substantially being integral with,fixedly attached to, said rotatable index setting knob and insertableinto and retractable from any selected one of said index settingopenings.